<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		#box{
			width: 200px;
			height: 200px;
			background: red url() 0 0 no-repeat;
		}
	</style>
	<script>
		
		window.onload=  function() {

			box = document.getElementById("box");

			is = true;

			box.onclick= function () {
				if(is){
					box.style.width = "400px";
					box.style.height = "400px";
					is=false
				}else{
					box.style.width = "200px";
					box.style.height = "200px";
					is=true
				}
			}
			
		}
	</script>
</head>
<body>
	<div id="box"></div>
</body>
</html>